function indexSearch(list, element) {
    let currentIndex,
        currentElement,
        minIndex = 0,
        maxIndex = list.length - 1;
    while (minIndex <= maxIndex) {
        currentIndex = Math.floor((maxIndex + maxIndex) / 2);
        currentElement = list[currentIndex];
        if (currentElement === element) {
            return currentIndex;
        }
        if (currentElement < element) {
            minIndex = currentIndex + 1;
        }
        if (currentElement > element) {
            maxIndex = currentIndex - 1;
        }
    }
    return -1;
}